1. Field of the Invention
This invention relates to a quick connector, especially for smooth pipes for hydraulic or pneumatic pressure or vacuum testing.
2. Description of the Related Technology
Such quick connectors are used for pressure testing heat exchanger pipes in heating plants or cooling plants for example. The quick connector is fitted on the open end of a pipe, on the outside or the inside, while generally speaking a connecting element, especially in plug form, can be splayed in the radial direction so that the quick connector engages the inner or outer wall of the pipe forcefully through friction. The connecting element can also be formed as a slotted sleeve engaging round the outside. This connecting element is then splayed in or splayed out slightly in the radial direction by an actuating device, so that frictional engagement is produced between the pipe wall and housing of the quick connector.
Such a quick connector should offer an especially simple facility for coupling up, since in mass production a plurality of such smooth pipes have to be tested. In addition the retaining force should be especially high, so that the testing can be carried out safely even with high pressures in the region of about 50 bar or more.
Accordingly the invention is based on the object of further improving a quick connector in respect of handling and retaining force.
A quick connector for pipes for pressure or vacuum testing includes a tubular housing extending in an axial direction, a spreadable connecting element mounted within the tubular housing, formed as a sleeve and configured to clamp a pipe in a connected position, and an actuating device configured to act upon the connecting element to release the connecting element. The actuating device includes a hand lever extending in the axial direction of the housing. The hand lever has an actuating push rod that extends through an outer wall of the housing. The quick connector includes further a piston positioned within the housing and configured to be movable in the axial direction by the actuating device, and a compression spring positioned within the housing and configured to bias the piston in a connected position.
A particularly simple construction of the quick connector arises from the proposed design of the quick connector, wherein a piston is guided in the housing and can be shifted axially by the actuating device. In addition the retaining force of the quick connector is increased by biasing the piston into the connected position by a compression spring, since very strong compression springs can be fitted, which then bias the connecting element with a correspondingly high splaying force.
In the preferred implementation a splaying piston is interposed between the piston and the connecting element in the housing of the quick connector and acts on the connecting element with a high splaying force by means of an annular wedge surface, (the connecting element being formed as an internal or external connection and being quickly interchanged through a sleeve for the current pipe diameter). In addition, this interposed splaying piston has the particular advantage that an annular piston surface of larger diameter can be provided on the end surface facing away from the pipe. An additional force of application on the connecting element is created by this, so that the splaying piston is forced in the direction of the connecting element as the fluid pressure (test pressure) rises and the retaining force of the frictional engagement is increased proportionally with the test pressure.
Furthermore the actuating device is preferably in the form of a hand lever, which is mounted at the forward end of the quick connector. A large lever length for counteracting the compression spring can be provided in this way. The hand lever preferably comprises an actuating push rod which is passed through the outer wall of the housing to the piston at an angle of about 45E. A good application of force can be achieved by this when uncoupling the quick connector. The end surface of the piston on the pipe side preferably serves at the same time as a stop surface for the inserted smooth pipe.
Two embodiments of the quick connector will be explained in more detail and describe with reference to the drawings, in which: